From patchwork Sun Dec 8 18:24:17 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Florian Westphal X-Patchwork-Id: 1205721 X-Patchwork-Delegate: fw@strlen.de Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (no SPF record) smtp.mailfrom=lists.01.org (client-ip=2001:19d0:306:5::1; helo=ml01.01.org; envelope-from=mptcp-bounces@lists.01.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=strlen.de Received: from ml01.01.org (ml01.01.org [IPv6:2001:19d0:306:5::1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 47WF9s6yx1z9sP3 for ; Mon, 9 Dec 2019 05:25:21 +1100 (AEDT) Received: from ml01.vlan13.01.org (localhost [IPv6:::1]) by ml01.01.org (Postfix) with ESMTP id 903B0101134EC; Sun, 8 Dec 2019 10:28:41 -0800 (PST) Received-SPF: Pass (mailfrom) identity=mailfrom; client-ip=2a0a:51c0:0:12e:520::1; helo=chamillionaire.breakpoint.cc; envelope-from=fw@breakpoint.cc; receiver= Received: from Chamillionaire.breakpoint.cc (Chamillionaire.breakpoint.cc [IPv6:2a0a:51c0:0:12e:520::1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id 5DF66101134E9 for ; Sun, 8 Dec 2019 10:28:39 -0800 (PST) Received: from fw by Chamillionaire.breakpoint.cc with local (Exim 4.92) (envelope-from ) id 1ie1F4-0003Qo-Tq; Sun, 08 Dec 2019 19:25:14 +0100 From: Florian Westphal To: Cc: Florian Westphal , Peter Krystad Date: Sun, 8 Dec 2019 19:24:17 +0100 Message-Id: <20191208182417.16789-2-fw@strlen.de> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20191208182417.16789-1-fw@strlen.de> References: <20191208182417.16789-1-fw@strlen.de> MIME-Version: 1.0 Message-ID-Hash: SF3AED57JTA2CWQWI2PW6WJYM266Y6NR X-Message-ID-Hash: SF3AED57JTA2CWQWI2PW6WJYM266Y6NR X-MailFrom: fw@breakpoint.cc X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; suspicious-header X-Mailman-Version: 3.1.1 Precedence: list Subject: [MPTCP] [PATCH 22/48] mptcp: add subflow write space signalling and mptcp_poll List-Id: Discussions regarding MPTCP upstreaming Archived-At: List-Archive: List-Help: List-Post: List-Subscribe: List-Unsubscribe: Add new SEND_SPACE flag to indicate that a subflow has enough space to accept more data for transmission. It gets cleared at the end of mptcp_sendmsg() in case ssk has run below the free watermark. It is (re-set) from the wspace callback. This allows us to use msk->flags to determine the poll mask. Co-developed-by: Peter Krystad Signed-off-by: Peter Krystad Signed-off-by: Florian Westphal --- net/mptcp/protocol.c | 52 ++++++++++++++++++++++++++++++++++++++++++++ net/mptcp/protocol.h | 1 + net/mptcp/subflow.c | 2 ++ 3 files changed, 55 insertions(+) diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index 22a8b125139f..7d0c2ba212e1 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -134,6 +134,22 @@ static int mptcp_sendmsg_frag(struct sock *sk, struct sock *ssk, return ret; } +static void ssk_check_wmem(struct mptcp_sock *msk, struct sock *ssk) +{ + struct socket *sock; + + if (likely(sk_stream_is_writeable(ssk))) + return; + + sock = READ_ONCE(ssk->sk_socket); + + if (sock) { + clear_bit(MPTCP_SEND_SPACE, &msk->flags); + smp_mb__after_atomic(); + set_bit(SOCK_NOSPACE, &sock->flags); + } +} + static int mptcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) { struct mptcp_sock *msk = mptcp_sk(sk); @@ -178,6 +194,7 @@ static int mptcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) if (copied > 0) ret = copied; + ssk_check_wmem(msk, ssk); release_sock(ssk); release_sock(sk); return ret; @@ -275,6 +292,7 @@ static int mptcp_init_sock(struct sock *sk) struct mptcp_sock *msk = mptcp_sk(sk); INIT_LIST_HEAD(&msk->conn_list); + __set_bit(MPTCP_SEND_SPACE, &msk->flags); return 0; } @@ -554,6 +572,13 @@ static void mptcp_sock_graft(struct sock *sk, struct socket *parent) write_unlock_bh(&sk->sk_callback_lock); } +static bool mptcp_memory_free(const struct sock *sk, int wake) +{ + struct mptcp_sock *msk = mptcp_sk(sk); + + return wake ? test_bit(MPTCP_SEND_SPACE, &msk->flags) : true; +} + static struct proto mptcp_prot = { .name = "MPTCP", .owner = THIS_MODULE, @@ -569,6 +594,7 @@ static struct proto mptcp_prot = { .hash = inet_hash, .unhash = inet_unhash, .get_port = mptcp_get_port, + .stream_memory_free = mptcp_memory_free, .obj_size = sizeof(struct mptcp_sock), .no_autobind = true, }; @@ -778,8 +804,34 @@ static int mptcp_stream_accept(struct socket *sock, struct socket *newsock, static __poll_t mptcp_poll(struct file *file, struct socket *sock, struct poll_table_struct *wait) { + const struct mptcp_sock *msk; + struct sock *sk = sock->sk; + struct socket *ssock; __poll_t mask = 0; + msk = mptcp_sk(sk); + lock_sock(sk); + ssock = __mptcp_fallback_get_ref(msk); + if (ssock) { + release_sock(sk); + mask = ssock->ops->poll(file, ssock, wait); + sock_put(ssock->sk); + return mask; + } + + release_sock(sk); + sock_poll_wait(file, sock, wait); + lock_sock(sk); + + if (test_bit(MPTCP_DATA_READY, &msk->flags)) + mask = EPOLLIN | EPOLLRDNORM; + if (sk_stream_is_writeable(sk) && test_bit(MPTCP_SEND_SPACE, &msk->flags)) + mask |= EPOLLOUT | EPOLLWRNORM; + if (sk->sk_shutdown & RCV_SHUTDOWN) + mask |= EPOLLIN | EPOLLRDNORM | EPOLLRDHUP; + + release_sock(sk); + return mask; } diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h index e67057a7abca..5c1c0551b809 100644 --- a/net/mptcp/protocol.h +++ b/net/mptcp/protocol.h @@ -54,6 +54,7 @@ /* MPTCP socket flags */ #define MPTCP_DATA_READY BIT(0) +#define MPTCP_SEND_SPACE BIT(1) /* MPTCP connection sock */ struct mptcp_sock { diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c index 7a16e5a3a124..ddbec9b82e4e 100644 --- a/net/mptcp/subflow.c +++ b/net/mptcp/subflow.c @@ -531,6 +531,8 @@ static void subflow_write_space(struct sock *sk) sk_stream_write_space(sk); if (parent && sk_stream_is_writeable(sk)) { + set_bit(MPTCP_SEND_SPACE, &mptcp_sk(parent)->flags); + smp_mb__after_atomic(); sk_stream_write_space(parent); } }